Current estimates report that about 300,000 Americans have been diagnosed with multiple sclerosis (MS) with an incredible 10,000 new cases being diagnosed each year. While there is a small hereditary component, by and large, most cases seem to just happen without an identifiable cause. Over the past few decades, the medical literature has focused on the possibility of some infectious agent playing a causal role and candidates have included the bacterium Chlamydia pneumoniae, as well as various viruses including Epstein-Barr and human herpes virus type six.
MS is considered an "autoimmune disorder," meaning a disease characterized by the immune system reacting against the body. In MS, this misdirected immune response is directed against myelin, the protective insulation coating around brain neurons. Ultimately, collections of damaged neurons form a hard or sclerotic plaque in the brain and appear in multiple areas -- hence the name multiple sclerosis.
The mainstay of treatment for MS these days is the use of so-called "immunomodulatory therapy," or treatments designed to modulate the overactive immune response. Common approaches using this approach involve the frequent injection of various forms of synthetic interferons. This approach has been shown to reduce the risk of new events or exacerbations of MS by as much as 28-30 percent. Unfortunately, this type of medical intervention is often associated with significant side effects and reports of patients feeling "flu-like symptoms" in as many as 78 percent of cases.
One interesting observation that has puzzled MS researchers over the past 30 years is the peculiar geographic distribution of the disease. It turns out that people who spend their early lives in northern latitudes have a significantly increased risk for developing the disease. More recently it has been demonstrated that the same is true in the southern hemisphere. So the farther away you live from the equator, either north or south, the more at risk you are for developing MS.
In trying to unravel this relationship, scientists concluded that perhaps living farther away from the equator might relate to MS risk because of a lack of sunshine. It is known that sunshine has a role to play in immune function, so scientists thought that perhaps a lack of sun exposure during winter made people more susceptible to the disease. But one other connection to sun exposure began to emerge. It is known that one of the key physiological events triggered by sun exposure is the body's production of vitamin D. Interestingly, research clearly demonstrated that MS patients have remarkably lower levels of vitamin D compared to non-afflicted individuals.
NOTE: Vitamin D can be toxic in large doses. People with MS should be aware of these findings, but should also discuss them with their neurologist.
These findings dovetailed nicely with the newly emerging reports expanding the understanding of the role of vitamin D in human physiology, not just for bone health, but as a key player in immune function as well. To put the idea of vitamin D's relationship to MS to the test, researchers in Toronto -- led by Jodie Burton, M.D. -- studied 49 MS patients for one year. Twenty-five of the patients received vitamin D in a dosage increasing up to 40,000 units daily, which was then reduced over the one-year period. The control group was given no vitamin D supplementation.The results of their study, published in a recent issue of the journal Neurology, were astounding. The group receiving the vitamin D demonstrated a remarkable 41 percent reduction in new MS events, a figure that markedly exceeds what is claimed by the standard drug treatment discussed above. What's more, the treatment group actually demonstrated improvement in physical function, a finding not seen in the control group.There were no meaningful side effects in the group receiving the vitamin D treatment and researchers demonstrated that blood calcium levels remained perfectly normal throughout the test, even at the very highest dosages of vitamin D. This was an important part of the study since concern has been raised that high vitamin D levels might increase blood calcium levels. The authors reported:
We have demonstrated that vitamin D intake well above current recommendations and (vitamin D) levels well beyond the physiologic range, do not expose patients with MS to adverse biochemical or clinical events. Compared to a control group whose intake of vitamin D generally exceeded North American recommendations, only those on the treatment regimen had evidence of immunologic effects.
As a practicing neurologist actively treating patients with this sometimes-devastating disease, this new report has clearly offered a potentially new and powerful tool for my toolbox. Vitamin D is incredibly inexpensive, and, according to this report, safe and powerfully effective as well. Clearly we will need to see more research to confirm these findings, but what a breath of fresh air it is that such a wonderful gift might be available at the health food store, or even from the good old sun itself.